One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,7)(3,6,8,5)(9,10)(11,15)(12,19)(13,14)(16,20)(17,21)(18,24)(22,23)(26,31)(27,33)(29,37)(36,40)(3,8)(5,6)(11,17)(15,21)(18,23)(22,24)(25,26,30,31)(27,32,33,28)(29,34,37,39)(35,40,38,36)(1,3)(2,5)(4,8)(6,7)(10,14)(15,21)(16,19)(22,24)(25,27,30,33)(26,32,31,28)(29,38,37,35)(34,36,39,40)(3,8)(5,6)(9,10)(11,15)(12,16)(13,14)(17,21)(18,22)(19,20)(23,24)(25,27)(26,32)(28,31)(29,35)(30,33)(34,40)(36,39)(37,38) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,11)(10,15)(12,18)(13,17)(14,21)(16,22)(19,24)(20,23)(25,28,30,32)(26,33,31,27)(29,36,37,40)(34,38,39,35)(1,2)(3,6)(4,7)(5,8)(9,12)(10,16)(11,18)(13,20)(14,19)(15,22)(17,23)(21,24)(25,29,30,37)(26,34,31,39)(27,35,33,38)(28,36,32,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.